title: Effective GC-MS procedure for detecting iso-LSD in urine after base-catalyzed conversion to LSD.
abstract: A sensitive method is described to detect isolysergic acid diethylamide (iso-LSD) in urine. The compound was extracted from urine and converted to a C-8 carbanion by sodium ethoxide in ethanol. Protonation of the carbanion by water selectively produced LSD. The conversion of iso-LSD to LSD was almost quantitative (98%). The product was purified by solid-phase fractionation and acid-base separation techniques. The trimethylsilyl derivative of LSD was detected by a gas chromatography-mass spectrometry method. The overall recovery of the procedure was approximately 69%. Quantification of iso-LSD was linear over the concentration range 50-2000 ng/L. In specimen analysis, iso-LSD was detected when the LSD concentration was below the limit of the detection (50 ng/L) of the procedure. Because iso-LSD is a byproduct of illicit preparation of LSD, presence of iso-LSD in urine is an indication of LSD use.
authors.affiliation: Navy Drug Screening Laboratory, San Diego, CA 92134, USA.
authors.forename: E D
authors.initials: ED
authors.lastname: Clarkson
authors.forename: D
authors.initials: D
authors.lastname: Lesser
authors.forename: B D
authors.initials: BD
authors.lastname: Paul
mesh_terms: D000431:Ethanol / Q000031:analogs & derivatives / Q000494:pharmacology; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D007536:Isomerism; D008238:Lysergic Acid Diethylamide / Q000652:urine*; D015394:Molecular Structure; D012680:Sensitivity and Specificity; D019966:Substance-Related Disorders / Q000652:urine; D013997:Time Factors
chemical_list: C098088:sodium ethoxide; D000431:Ethanol; D008238:Lysergic Acid Diethylamide